Is minoxidil safe?

In this article:

• Is minoxidil safe?
• Long-term use
• Safety risks
• Misuse
• Contraindications
• How to use minoxidil safely
• The bottom line

In this article

• Is minoxidil safe?
• Long-term use
• Safety risks
• Misuse
• Contraindications
• How to use minoxidil safely
• The bottom line

Minoxidil is the generic name for Rogaine, a hair growth medication for men and women. Topical minoxidil is sold over the counter in 2% and 5% solutions or foams. There is also a prescription-strength oral minoxidil for people whose high blood pressure can’t be controlled with other medications. Low-dose oral minoxidil is sometimes prescribed to help with hair loss in both women and men, though this is an off-label use.

Hair loss is the most common and well-known use of this medication. If you’ve recently begun using minoxidil or are considering using it long-term, you might be wondering: Is minoxidil safe? The answer is that it’s widely considered a safe medication when used under a healthcare professional’s supervision.

Is minoxidil safe?

Yes, minoxidil is considered safe for use in hair growth in men and women. “Minoxidil has a strong safety record and has been used for decades, both as a topical solution and as an oral medication,” says Arjun Dupati, MD, a dermatologist at Apollo Dermatology.

While it’s most commonly used to treat male-pattern baldness (androgenic alopecia), topical Minoxidil is FDA approved to treat female-pattern hair loss (FPHL). “For women, minoxidil is absolutely an option and often a first-line treatment for female pattern hair loss,” Dr. Dupati adds. 

While topical minoxidil can be used on beards and other areas of the body, this use would be considered off-label. Plus, it may lead to additional side effects, such as itchiness or redness at the application site. “People do use it off-label for beard growth and eyebrows, and while many tolerate it well, those areas can be more sensitive to irritation,” Dr. Dupati says.

“The topical version is generally labeled for adults 18 and older, and we are careful with use in younger patients or older adults with other health conditions,” Dr. Dupati explains. Of note, topical minoxidil is considered most effective for people aged 40 and younger. Additionally, for those older than 40 years, there are many other causes of hair loss that providers may evaluate for before using minoxidil.

Common side effects you might experience early on

Most people don’t experience any side effects of minoxidil, but you may notice the following, especially when you begin treatment:

• Itching of your scalp area
• Headache
• Increase in facial hair growth
• Seborrheic dermatitis (greasy, itchy scaly patches on scalp or face)
• Increase in hair loss
• Rare systemic absorption causing increased heart rate, swelling, or dizziness 

Initial hair loss is considered temporary shedding, when older, thin hair is pushed out to make room for new hair growth. It typically subsides within eight weeks of treatment.

Is minoxidil safe for long-term use?

Yes, clinical studies have found that long-term topical minoxidil use is generally safe for healthy individuals. Adverse side effects, like hypotension (low blood pressure) or tachycardia (increased heart rate), are rare.

Not only is it safe, but it’s meant to be used on an ongoing basis because hair thinning and loss are chronic conditions, explains Kari M. Ford, director of pharmacy at Saint Anthony Hospital’s SAH Pharmacy in Chicago. “Hair growth with minoxidil is not permanent, so chronic, indefinite use is necessary to maintain the new hair growth,” she adds.

Does the body build tolerance to minoxidil? 

Some people notice that minoxidil seems to work less effectively as time goes on, but it’s not because you’ve built a tolerance to the medication, or even that it’s become less effective. “True tolerance is not really what happens, but some patients do notice their results plateau over time, which usually reflects the natural progression of hair loss rather than the medication failing,” Dr. Dupati explains. In other words, the medication can no longer overcome the changes in your hair follicles and stimulate new growth.

What happens if you stop?

Unfortunately, minoxidil doesn’t cause permanent hair regrowth. “If you stop using minoxidil, the hairs that were being supported will gradually shed over the following months, and you typically return to where you would have been without treatment,” says Dr. Dupati. “This is why I always tell patients that starting minoxidil is a commitment.”

 Once you stop taking minoxidil, your hair “will return to its baseline status within three to six months,” Dr. Ford says. 

Specific safety risks

Though rare, some people may experience more severe adverse effects after using minoxidil.

Scalp irritation and contact dermatitis

Scalp irritation or contact dermatitis (itchy, inflamed skin) is possible when using minoxidil. This is commonly due to a preservative in the medication’s formula called propylene glycol, explains Farah Moustafa, MD, a dermatologist at Tufts Medical Center. “In these cases, we can have patients switch to topical foam, which can be better tolerated,” Dr. Moustafa says. Topical minoxidil is available as a foam, liquid, or spray. Use caution with online platforms that use compounded hair loss treatments, as compounded drugs are not FDA approved, which means the FDA has not evaluated their safety, effectiveness, or quality prior to marketing. Using a lower dosage or switching to an alternative hair loss treatment may work too if issues persist.

RELATED: Minoxidil alternatives: What can I take instead of minoxidil?

Cardiovascular concerns

“Cardiovascular effects like a faster heart rate, lightheadedness, swelling in the ankles, or fluid retention are uncommon at the low doses we use but worth knowing about,” Dr. Dupati says. The topical version is less likely to cause these symptoms, but they are possible because minoxidil is a vasodilator that relaxes and widens blood vessels. For some, this can rapidly lower blood pressure. Though rare, if you notice any of these side effects, you should contact your healthcare provider right away.

Hypertrichosis

Hypertrichosis, or excessive hair growth, is another possible adverse reaction to topical minoxidil. “This is primarily seen in women with increased hair growth on the face (cheeks and forehead),” Dr. Ford says. It can occur if the topical form spreads to unintended areas, such as on a pillowcase that transfers to the face. Or, it can occur if the medication is absorbed systemically. The solution is usually to stop the medication, which should reverse the hair growth.  

The dangers of misuse and overdose

Topical overuse or misuse is usually not a concern with minoxidil, according to Dr. Moustafa; however, rare, dangerous systemic absorption may occur. 

“The concern from misuse is largely due to ingestion, by a child or animal, of the topical medication,” Dr. Moustafa warns. “Animals do not have the enzyme needed to break down the medication, and if they ingest it can cause cardiovascular issues and even death.” 

Who should exercise caution?

Minoxidil is not a one-size-fits-all solution for hair loss, and some individuals should exercise caution or use an alternative treatment. Minoxidil users should take care to store it safely away from children, adolescents, and animals.

Individuals with underlying heart conditions

Though rare, if topical minoxidil is systemically absorbed (into the body, not just the skin), it can cause side effects such as dilated blood vessels and lowered blood pressure. That’s why patients with heart disease or other underlying medical conditions “should weigh the risks versus benefits when taking minoxidil,” Dr. Ford advises. For these individuals, it is best to discuss with their health care providers before using the product in spite of it being available over the counter.

Pregnant and breastfeeding mothers

Animal studies have found adverse effects from using minoxidil during pregnancy. Since there is no human data proving otherwise, it’s recommended not to use it if you’re expecting. Likewise, minoxidil is excreted into breast milk and is not typically recommended during breastfeeding.

People taking other medications

You should always share a list of all medications you are taking with your provider or pharmacist before starting minoxidil treatment, as minoxidil can interact with certain prescriptions. “Minoxidil can interact with other blood pressure medications and certain heart medications, so a complete medication list is essential before starting,” Dr. Dupati says. It also interacts with erectile medications such as Viagra (sildenafil).

 How to use minoxidil safely

The safest way to use minoxidil is to follow your provider’s instructions and monitor your body’s response. Additionally, Dr. Dupati suggests that you:

• Apply minoxidil to a dry scalp and let it fully absorb before lying down or using hair styling products to prevent unwanted spread of the medication.
• Wash your hands thoroughly after applying it so you don’t transfer it to your face or to family members or pets.
• Take only the recommended dose; don’t double up if you miss a dose or use more, thinking it will work faster.
• Seek medical advice from your healthcare provider right away if you notice swelling, a racing heart, dizziness, or unwanted hair growth in new areas.
• Store the medication out of reach of children and pets.

The bottom line

Topical minoxidil is a generally safe hair regrowth treatment that can be used by men and women aged 18 and older. People with underlying heart conditions or who take heart medication should use caution with this medication. Pregnant and breastfeeding people should avoid using minoxidil. Adverse effects aren’t common, but can include cardiovascular symptoms, skin irritation, and excessive hair growth.  

Although most healthy people can use minoxidil without issues, it should only be used after consulting your healthcare provider and following their specific instructions, and you should promptly reach out to your provider if you have side effects, questions, or concerns.